If I put my potted gerbera daisy outside will it weather the winter in an area that gets snow and may get down to 20 degrees?
It will survive those temperatures just fine. You may put them in the ground. If you are concerned, then mulch them some to help.
Here is an article with more information: https://www.gardeningknowhow.com/ornamental/flowers/gerbera-daisy/growing-gerbera-daisies.htm